Head lice can walk from one head to another when the heads are touching for some time.

You are very unlikely to pick up head lice from brief contact with other people. The longer you have head to head contact with someone who has lice, the more likely it is you will get them too.

They can’t swim, fly, hop or jump. The idea that they can jump may have come from the fact that, when dry hair is combed, a head louse caught on the teeth of the comb is sometimes flicked off by static electricity (this is one reason why detection combing should be done with the hair damp).

You don’t get them from objects such as the chair back. Although it’s just possible that a louse might get from one head to another if a hat is shared, this is very unlikely. It’s not the way infection is usually caught.